1. Field of the Invention
The present invention relates generally to sports devices and more particularly to thos used for developing skills in sports which involve stroking at a ball while it is in midair.
In particular, it relates to a device to combat the injury commonly described as "tennis elbow" by providing a simple and effective means for allowing a player to develop the forearm extensor muscles, to learn and practice the correct handling of the racket and to develop skills in correctly hitting a ball.
2. Description of the Prior Art
Various techniques have been suggested to aid tennis players in improving their stroke. These include specially designed rackets or attachments to rackets, various captive ball devices and combinations of these.
Exemplifying the first group, U.S. Pat. No. 3,503,611 discloses a practice tennis racket which includes a ball catching bag disposed on one side of the face of the racket instead of strings. When the ball hits the center of the racket, the ball is caught in the bag, thereby indicating that the user has properly hit the ball.
This apparatus has several limitations. The racket is useful only in practice since the strings are removed. Further, the bag and the cover disposed over it gives the racket characteristics differing from an actual racket, specially as to weight and wind resistance.
Captive ball practicing devices are disclosed in U.S. Pats. Nos. 2,247,072 and 3,825,259 which teach a ball positioned on an elastic cord which is secured at both ends to appropriate mounting means. The ball is usually moveable along the length of the cord to allow positioning at various heights from the ground. When struck with a tennis racket the ball will move away from the racket to the full extension of the restraining cord, return and continue oscillating at decreasing amptitude until it returns to its original stationary position. U.S. Pat. No. 2,247,072 provides for a dampening mechanism which more rapidly decreases the oscillations.
In the captive ball type of practice device utilizing an elastic cord only the ability to hit the ball is developed and correctness of stroke is not indicated.
A still further type of tennis practice apparatus is that discribed in U.S. Pat. No. 3,231,271. The apparatus comprises various positioning means to indicate correct placement of the feet and racket prior to and after the stroke and a racket type instrument, having no strings and a break in the racket rim which allos the racket, on a correct stroke to pass through a set of mounted tennis balls which simulate a moving tennis ball in a succession of position. This device is similar to a captive ball type of apparatus, in that only the ability to hit the ball is tested.